Actuators typically are mechanical devices that are used for moving or controlling a mechanism or system and typically convert energy into some type of motion. Examples of actuators can be found in any number of applications encountered in every day life including automotive, aviation, construction, farming, factories, robots, health care, and prosthetics, among other areas.
Every mechanical system designed to move or control a mechanism or system must have one or more “prime movers” to provide the energy or work needed and one or more “transmissions” to convey the energy or work from the prime mover to the object that is desired to be moved. Prime movers typically convert electrical or chemical energy to mechanical energy in the form of forces and displacements.
Examples of prime movers may include combustion engines, electric motors, biological/artificial muscles, piezo-electrics, shape-memory-alloys, magnetostrictives and dielectrics, among others. Examples of transmissions may include levers, linkages, wheels, gears, pneumatics and hydraulics, among others.
Pneumatic and hydraulic transmission systems are generally known and typically include one or more actuators and one or more valves in communication with a pump or the like that provides fluid (typically hydraulic fluid, air or gas) to the system at a fixed pressure. Such systems tend to be inefficient, costly and noisy.
Operating these transmission systems gets very complex, particularly when used within a sophisticated system that requires precise movements and may be subject to pressure spikes and/or negative pressure transients or the like. Additionally, many systems, particularly mobile systems such as vehicles, aircraft, robotics, unmanned vehicles, among other mobile systems, require reliable constant performance with no chance of system failure while providing highly efficient operation in very demanding applications to ensure proper operation of the system at all times.
This is particularly true where the orientation of the system can have an effect on the operation of the system such as in aviation or robotics, for example. Traditional systems can only provide the appropriate fluid pressure to the system in certain orientations of the system which limits the system mobility.